Millimeter wave scanners and "backscatter" scanners I was reading about these new full body scanners that they're implementing in airports these days. The two types of scanners in use today are millimeter wave scanners and backscatter scanners. From what I've gathered, millimeter wave scanners transmit radio waves which penetrate the clothes and reflect off the body, revealing whats under the clothes. The backscatter devices on the other hand use x-rays. Can this backscatter technology penetrate the whole body, revealing the organs and whats inside the stomach etc, similar to what a hospital x-ray machine does? I read that to get more penetrating power, a higher dose of x-rays must be used, therefore lower doses of x-rays only reveal whats under the clothes, rather than inside the body, similar to what the millimeter wave scanners are capable of. Is that correct, are higher doses of x-rays required to reveal whats under the skin?